The present invention relates generally to a supplemental, on demand, nitrous oxide injection system especially well-suited for racing vehicles such as motorcycles, automobiles and watercraft. The present invention provides a supplemental nitrous oxide injection system capable of smooth and safe operation throughout the entire throttle range of virtually any internal combustion engine.
Nitrous oxide injection systems are known in the prior art. For example, Nitrous Oxide Systems, Inc. of Costa Mesa, Calif. provides a nitrous oxide injection system for motorcycles. This prior art system is shown schematically in FIG. 5 of this application. This particular prior art system only allows the entry of nitrous oxide when the vehicle is at, or above, 50% of wide open throttle ("WOT"). The present invention provides an injection system capable of safe and efficient operation from zero to 100% of wide open throttle.
The prior art includes the Grant U.S. Pat. No. 5,839,418 dated Nov. 24, 1998. This patent provides a fuel supply module positioned between the carburetor and intake manifold through which fuel and nitrous oxide are sprayed. The nitrous oxide and fuel thereafter mix in the intake manifold. However, the primary drawback of that system is that the nitrous oxide is introduced unevenly to the plurality of cylinders in the engine. Those cylinders that receive a higher proportion of nitrous oxide typically run hotter than the other cylinders, resulting in excessive wear caused by the heat. Another disadvantage of systems injecting the nitrous oxide into the intake manifold is that the pressurized nitrous oxide may accumulate in the intake manifold through leaky control valves. Such unwanted accumulations of nitrous oxide in the intake manifold can cause explosions when the engine is started.
The Norcia et al U.S. Pat. No. 4,683,843 dated Aug. 4, 1987 teaches an earlier system for injecting nitrous oxide through a plate mounted between the carburetor and intake manifold. This system has the inherent drawbacks described above with respect to the Grant U.S. Pat. No. 5,839,418.
The Wheatley U.S. Pat. No. 4,494,488 dated Jan. 22, 1985 also teaches a nitrous oxide injection system where the nitrous oxide is introduced through a plate between the carburetor and intake manifold. That patent is primarily concerned with prolonging the initial momentary burst of nitrous oxide into the fuel system upon activation of the nitrous oxide injection system.
The existing fogger (or mixer) nozzle technology that is used in the present invention is part of the prior art as shown in U.S. Pat. Nos. 4,827,888 and 5,699,776.
The present invention provides a supplemental nitrous oxide injection system wherein a proper ratio of nitrous oxide to fuel is throttle controlled, and is preferably proportional to, zero to 100% of wide open throttle (W.T.). The present invention provides a steady and proportional flow of nitrous oxide which avoids the difficulty of the prior art systems in dealing with the initial momentary burst of nitrous oxide and the ensuing relatively uneven supply of nitrous oxide relative to fuel, especially when the nitrous oxide is first introduced into the fuel system. This variable flow control design allows the driver of the vehicle to use the normal throttle control for the engine to also control the flow rate of the nitrous-oxide injection system.
The present invention also provides a unique and novel method of introducing the supplemental nitrous oxide and fuel directly into each combustion chamber of the engine rather than into the region between the carburetor and intake manifold. The present invention thereby avoids the uneven distribution of nitrous oxide to multiple cylinders of an engine. The present invention provides a uniform flow of nitrous oxide to each cylinder, equalizing the fuel mixture ratio in each cylinder and minimizing those instances of the cylinders running hot and causing engine damage.
The present invention also provides a relatively safe system for nitrous oxide injection in that the nitrous oxide bypasses the carburetor and intake manifold and therefore is unable to accumulate in the engine intake manifold through a leaky solenoid. Also, the possibility of low fuel pressure causing the fuel mixture to "lean out" to the point of causing engine damage is reduced by interlocking the "arming" of the system with the presence of adequate fuel pressure.